We propose to continue our studies of the cell physiology of secretion and of the pathogenesis and exocrine gland dysfunction of cystic fibrosis. These studies will include the following: 1) Completion of the study of calcium metabolism in isolated rat and human parotid acinar cells in vitro; 2) Continuation of the studies of stimulus-secretion coupling in isolated human and rat parotid acinar cells; 3. Preliminary studies of the function of isolated parotid acinar cells from rats undergoing pharmacological induction of changes resembling those of cystic fibrosis (the changes will be induced by chronic administration of isoproterenol, reserpine, or both; 4. Studies of the function of the tracheal mucosa and of individual tracheal glands of the cat and ferret trachea in vitro.